Electric motor fuel pumps mounted within a vehicle fuel tank have been used to supply fuel under pressure to the vehicle engine. Ingestion of fuel vapors by the fuel pump reduces the efficiency of the fuel pump and in extreme cases, can cause vapor lock or other operational problems. Especially with turbine vane fuel pumps, it is important to limit the vapor intake of the fuel pump because these fuel pumps do not sufficiently purge themselves of vapor under adverse temperature or other vapor generating conditions.
Some fuel pumps utilize a bag shaped filter which defines an enclosure through which fuel is drawn into the inlet of the fuel pump. During use of the fuel pump, some of the vapor drawn into the enclosure of the filter may separate from the liquid fuel and collect adjacent the upper wall of the filter forming a large volume of vapor bubbles. While some current fuel pumps can sufficiently process small amounts of vapor, it is undesirable to draw a large amount of vapor into the fuel pump due to the decrease in efficiency of the fuel pump as well as the potential for vapor lock or other adverse affects.